Why 11-beta-hydroxylase deficiency causes hypertension even though it results in reduced aldosterone synthesis:

" because of overproduction of cortisol precursors that are, or are metabolized to, mineralocorticoid agonists." Source

• Cutaneous T cell lymphoma - usually limited to the skin. Looks like pityriasys versicolor.
• benign course
• Phototherapy is a treatment.
• Looks eczematous or like psoriasis; often initially on buttocks.

[!INFO] Mnemonics
REDMAN or SCALP-ID
REDMAN : Eczema / psoriasis, Drugs, Malignancy (mycosis fungoides, CTCL, Autoimmune, No identifiable cause)

SCALP-ID

• Either sporadic or #autosomalDominant

• Normally, the kidney deactivates cortisol via the enzyme 11-beta-dehydrogenase isozyme 2 to inactive cortisone, thus 'protecting' it's mineralocorticoid receptors from the effects of cortisol. Source
• In ectopic ACTH mediated Cushing's syndrome, this inactivation is overwhelmed and cortisol acts on the aldosterone receptors -> producing hypokalemia.
• #2021GM-JUL/Q16 Deficiency of 11-beta-dehydrogenase occurs in "apparent mineralocorticoid excess".
  #2021GM-JUL/Q16

Apparent mineralocorticoid excess syndrome

[!TIP] Mnemonic: Similar to Conn's syndrome but with low renin and aldosterone.

Caused by deficiency of 11-beta-dehydrogenase.
Features:

• Hypokalemia

• Metabolic alkalosis

• Low plasma renin activity

• Low plasma aldosterone levels

• Chronic liquorice (licorice) ingestion causes a similar picture. It inhibits 11-beta-dehydrogenase.

Organism excreted via urine of infected animal. (Only a minority of humans excrete organisms in urine - that's from second week onwards)

• Conjunctival suffusion is an important sign - minority have a sub conjunctival haemorrhage; but suffusion is the commoner manifestation.
  Leptospiraemic phase = septicaemic phase.
  Blood and CSF culture won't be positive in the immune phase.

Usually non-oliguric and hypokalemic.

⭐Definition of AIDS :

• a CD4 cell count <200 cells/microL or
  :read the aids defining illnesses table:

• progressive, multifocal, subacute focal neurological deficits that vary depending on the site of the lesion and include a spectrum of presentations including cognitive impairment, limb ataxia, gait ataxia, hemiparesis, ⭐hemianopia, and aphasia.
• Optic nerve and Spinal cord are usually spared.
• T lymphocytes play a major role in the normal immune response to JC virus.
• PML is rare but fatal is most cases.
• JC is a DNA virus.

Streptococci

Comparison of some medically important streptococci

[!TIP] Common terminology

• Pyogenes = GABS, Group B strep - Agalatiae; Pneumococcus = Strep pneumonia.

• Scarlet fever (not a late complication but a manifestation of infection)

• [[Nephrology miscellaneous#Membranoproliferative glomerulonephritis|Membranoproliferative(aka mesangioproliferative,aka mesangiocapillary) glomerulonephritis]]

[!INFO] Membranoproliferative and Mesangioproliferative are described under "acute nephritic syndromes" in Harrison's
This probably means they present more often as nephritic syndromes but also can have some proteinuria.

• Type 1: subendothelial immune complex deposition (or interposition of mesangial cells in the subendothelial space) -> splitting of capillary basement membrane -> tramline appearance. (Mnemonic: "All aboard the proliferative train") -> Tramlines
  • Type 1 MPGN is commonly associated with chronic hepatitis C infection
  • Nephrotic range proteinuria is a poor prognostic marker.
  • 
  • linear intramembranous-membranous deposits
    Causes of membranoproliferative glomerulonephritis

1. Autoimmune
2. Chronic infections

There is (From Harrison's)

1. Mesangial expansion +/- mesangial hypercellularity.
2. Single contoured capillary walls
3. Mesangial immune deposits.

• Presents with varying degrees of proteinuria and commonly haematuria.
  • Isolated haematuria -> very benign course;
    proteinuria + -> increased risk of renal failure.
• Most cases are caused by [[#IgA nephropathy]].
• Falciparum malaria is a cause.

C3 glomerulopathies

• Two types: Dense deposit disease (DDD) and C3 glomerulpathy. (C3GN)
• Defined by C3 mediated glomerulonephritis with no immunoglobulin involvement.
• C3 levels are low with normal C4 levels.
• The histological patterns of C3 glomerulopathies is most commonly membranoproliferative or mesangioproliferative.

• Autoimmune pancreatitis Type I (the commonest type) is seen in men. IgG4 positive with dense lymphoplasmacytic infiltrate.
  • Autoimmune pancreatitis responds well to steroids and lack of response should arouse suspicion of another diagnosis.
  • occurs independantly of trypsin activation.
• Autoimmune pancreatitis type II:
  • Main presenting feature is extrapancreatic symptoms.
  • Obstruction occurs early.
• Smoking is a risk factor -> smoking cessation is recommended in management.
• Pain: NSAIDS, tramadol, coeliac nerve block, TCA antidepressants for chronic pain, pregabalin.
• Steatorrhoea: usually occurs with long standing chronic pancreatitis. Enzyme supplements are given.
  • note that inadequate pancreatic bicarbonate secretion also contributes by ?inhibiting enzyme activation in the duodenum
  • Fat intake should NOT be reduced - will only worsen malnutrition.
• AKA type 3c diabeties or pancreatogenic diabetes.
• Occurs after many years of disease progression. (usually after the development of exocrine failure and malabsorption)
• A type of 'brittle' diabetes : patients have insulin deficiency (but rare ketosis) and also glucagon deficiency so they develop hypoglycaemia very easily while on treatment.
• creatine kinase, aminotransferases, LDH and aldolase are all raised.
  • Anti-Jo is more commonly seen in polymyositis than dermatomyositis.
  • Mnemonic: Jolly Polly

The surprising ones are highlighted; basically, myopathies tend to cause proximal symmetrical weakness; distal weakness is more likely due to nerve issues.

Paraneoplastic Dermatoses

Source

These are the Dermatoses which almost always occur with a malignancy.
| Lesion | Association | Mnemonic |
| ------------------------------------ | ----------------------------------------------------------- | ----------------------------------------------------------------------------- |
| Tripe palm (aka pachydermatoglyphia) | Lung cancer, gastric cancer | Occurs together with ANM |
| Acanthosis nigricans Maligna (ANM) | Gastric Adenocarcinoma | AN is connected to things relating to fat / stomach / tummy |
| Erythema gyratum repens | pulmonary, oesophageal, breast | Forests (wood grain appearance of rash) are the lungs of the world |
| Acquired hypertrichosis lanuginosa | colorectal, pulmonary and breast | Hairy butt |
| Bazex syndrome | Aerodigestive | |
| Acquired ichthyosis | Lymphoma | Lymfishma |
| Dermatomyositis | Ovarian Ca, Lung CA | Common in women -> ovaries.
Also, lungs
Associated with "paired organs" |
| Migratory thrombophlebitis | Pancreatic CA | Let's assume scorpion stings also case thrombosis |
| Necrolytic migratory erythema | Glucagonoma | Always carry glucose while migrating |
| Pyoderma gangrenosum | myeloproliferative disorders | pyo/myo |
| Sweet syndrome | Haematologic malignancies | Sweets raise blood sugar |
| Tylosis | Oesophageal cancer | Tie a tie around the oesophagus |
| Leser-Trelat | Gastric and colorectal | |
| Paraneoplastic pemphigus | NHL, CLL, Castleman Disease, Thymoma | |
| Pytiriasis rotunda | Hepatocellular carcinoma, gastric and oesophageal carcinoma | |
| Palmoplantar keratoderma | Oeseophageal SQC | |
| Pyoderma gangrenosum | | |
| Sweet syndrome | AML, MDS, | |
| pyoderma gangrenosum | MDS, myeloma, leukemia | |
Bazex syndrome

Pytiriasis rotunda

Necrolytic Migratory Erythema

Type 1 = H+ secretion defect in DCT.

Basis is hyperkeratosis and epidermal papillomatosis as seen on histology. Black color is not due to melanin but due to the hyperkaratosis. Source

Endocrine (Cushing's and Acromegaly)
N if for iNjected Insulin and other drugs

aka acute febrile neutrophilic dermatosis.

• Dermal neutrophilic infiltration
• Peripheral neutrophilia.
• Paraneoplastic manifestation of AML and MDS
• "Amyloid" was meant to describe the starch like properties of the substance. Initially described as "waxy" and "lardaceous".
• Proteins which are normally soluble start getting deposited extracellularly as beta pleted fibrils.
  The four most common causes of systemic amyloid deposition are

(Both (AL and AA) have the beta pleted sheet structure) (Harrison's - page 804)

• Histological : Fat pad biopsy (less risk of bleeding)
• Organ biopsy is needed if a specific organ is involved.
• When Congo red stains binds to amyloid protein, it produces apple green birefringence.
• Looks similar to DM nephropathy but the staining characteristics are different (DM nephropathy is PAS and silver stain positive)
• purpura, petechiae, and ecchymoses following minor trauma ("pinch purpura")
• Appearance of periorbital purpura following a Valsalva maneuver or dependent positioning of the head.(Racoon eyes)
• Macroglossia (picture 16), waxy papules and plaques, enlarged shoulder pads, bullous lesions, and sclerodermatous changes in the skin may also be seen. (UpToDate)
• AL amyloidosis is Associated with plasma cell dyscrasia (multiple myeloma, waldenstrom macroglobulinemia)

The symptoms and signs of AL and AA cannot reliably be distinguished. - Harrison's

• Haemophillus influenzae can cause meningitis in babies and older adults.

• Newborns: Group B Streptococcus, S. pneumoniae, L. monocytogenes, E. coli
• Babies and young children: S. pneumoniae, N. meningitidis, H. influenzae, group B Streptococcus, M. tuberculosis
• Teens and young adults: N. meningitidis, S. pneumoniae
• Older adults: S. pneumoniae, N. meningitidis, H. influenzae, group B Streptococcus, L. monocytogenes
  Source